In the Ruby Collections course at Treehouse, you'll level up your Ruby knowledge and start learning about collections. We use two basic data structures to create collections in Ruby: arrays and hashes. These are both examples of "collections" and you’ll work with them a lot in your career as a Ruby programmer. During the course, we'll be writing simple programs that build on what we learned in this course and in previous courses.

In Ruby Loops, you'll learn how to automatically repeat statements using Ruby. You'll learn about the loop construct, including while loops, until loops, for loops, and more. You'll also learn the basics of iteration and then move on to creating a simple contact list management program.

PHP Functions allow you to combine several statements of code into a 'function'. These functions can then be called by their given name, and all of the code contained will run and return the results. This will drastically help you clean up code and use less repetitive code.

A collection of data is often represented in an app in some sort of list. In this course we will learn about the popular Android component called ListView to display and interact with a list of items. We will also learn about RecyclerView, a newer, more efficient version of ListView. We will see how to use some default components as well as building custom lists with our own layouts and adapters.

In Django Basics, you learned how to set up the skeleton of a video tutorial library. But for a real-world application, you’d probably want more flexibility and functionality in your websites. Django offers lots of built-in options for using templates to make your site dynamic and flexible, and makes it easy for you to build the extra things you need. In this course, learn about more complex template inheritance, how to make use of the vast array of built-in tags and filters Django has, and how to grow your own tags and filters for the functionality that Django doesn’t provide. By the time you finish this course, you will have a deeper understanding of how you can make Django’s templates work for your project, as well as a fully fleshed out video tutorial site!

This project will show you how to build a simple website using the PHP programming language. The web site, a media library, will let you organize and display your Books, Movies and Music. You could easily use this project to create a website that lets you organize and display any type of item: Branch Locations, Products, Services, Events, even Courses like we have here on Treehouse.

Building a PHP-driven page is the first step in mastering PHP. The true power of PHP shines when you connect it to a data source like an API or a Database. To introduce you to databases, we'll use an example project -- a Personal Media Library application. We'll refactor this project by replacing an associative array with a database to provide a more robust and scalable tool to store the data in the media library. In the process, you'll learn how to use PDO -- a PHP extension to communicate with a database. You'll also learn about relational databases including how to search for data across multiple tables, as well as how to add common web site features like search forms and pagination.